A. Mazaraei; A.R. Sirousmehr; Z. Babaei
Abstract
Drought stress, temporally or permanently, is a more limiting factor in growth and distribution of vegetation cover than other environmental factors. In order to study the effects of vesicular arbuscular mycorrhizal and drought stress on growth and yield of Milk thistle (Silybum marianum (L.) Gaertn.), a ...
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Drought stress, temporally or permanently, is a more limiting factor in growth and distribution of vegetation cover than other environmental factors. In order to study the effects of vesicular arbuscular mycorrhizal and drought stress on growth and yield of Milk thistle (Silybum marianum (L.) Gaertn.), a pot experiment was performed as factorial based on completely randomized design in three replications in the research greenhouse of Chahnimeh at the University of Zabol. Drought stress consisted of two levels including %60 and %30 of field capacity and full irrigation as control treatment. Three mycorrhizal fungi including Glomus mosseae, Glomus versiformis, and Glomus intraradices were investigated. The results showed that after starting of drought stress, vegetative characteristics such as number of capituls, number of seeds in capitul, 1000 seeds weight, leaf number and area, root length, number of minor branches, plant height, and dry weight of leaf, stem and root, significantly decreased with increasing drought stress. RWC of leaf was intensely affected by drought and decreased from 77.3 in control treatment to 57.01 in 30% of field capacity irrigation treatment. In addition, with increasing drought stress, the amount of phosphorus in leaves decreased and the amount of potassium increased. Osmotic adjustment in Milk thistle was increased in response to drought stress and leaf proline content increased (the highest 0.13 mg/g tissue in 30% of field capacity treatment); however, silimarin content decreased from 16.35 in full irrigation to 10.24 in 30% of field capacity treatment. Inoculation with VAM significantly increased vegetative indices, silimarin content (the highest in G. mosseae application and the lowest in control), plant RWC, and leaf content of P and K under drought stress conditions compared to uninoculated plants; however, the leaf proline content was low. In general, application of mycorrhizae fungi increased drought stress resistance in Milk thistle.
M.V. Sadeghi Sarvestani; S. Hosseinzadeh; M. Osfoori; V. Rowshan; M. Ghasemi nejad; M. Eghtedari
Abstract
Clostridium botulinum is one of the major causes of bacterial food intoxication especially in the vacuum-packed foods and meat products. Preventing such contamination is a major concern in the food industries. The current study was aimed to investigate the presence of Clostridium botulinum type A in ...
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Clostridium botulinum is one of the major causes of bacterial food intoxication especially in the vacuum-packed foods and meat products. Preventing such contamination is a major concern in the food industries. The current study was aimed to investigate the presence of Clostridium botulinum type A in the traditional dairy products and the possible effects of Teucrium polium L. essential oil(leaf and /or flower) on the growing of microorganism, in vitro. Out of 160 samples of traditionally made kashk and dough, only one sample was isolated (type A) using the selective culture, while, one sample of dough (1.25%) and two cases (3.75%) of kashk were respectively found positive to type A and B of the bacteria, using multiple PCR assay. The major components of the flower extract were: α-Pinene (16.67%) and Valerianol (8.32%), and for the leaf extract: α-Pinene (14.79%), Myrcene (10.9%) and Germacrene (10.44%), were the major components. In order to evaluate the anti-microbial effects of the leaf and flower, 10 µl of each extract was employed using the disc diffusion technique. At 40 and 80 µl/ml essential oil concentrations, the diameters of the growing inhibition zones were 9 and 8 millimeters for the leaf essential oil, and 12 and 8 millimeters for flower essential oil. The minimum inhibitory concentration (MIC) of both essential oilwas 160µl/ml. The results of the present study may recommend the use of Teucrium polium L. essential oil as a natural component to reduce and/or to inhibit the growing of Clostridium botulinum, in foodstuffs.